According to one embodiment, a grounding gasket includes a main body and a projecting part. The main body is configured to be interposed between a ground part and a substrate and contact the ground part and the substrate. The projecting part projects from the main body. The projecting part is configured to extend through a through-hole which is opened in the substrate, project to a side opposite to a side on which the ground part is located, and contact a conductive component mounted on the substrate.